Festo CPX-2AA-U-I, Электронное руководство

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5. Analogue output module CPX−2AA−U−I
5−28
Festo P.BE−CPX−AX−EN en 0503b
Data format VZ + 15 bits linear scaled"
The data range defined by the scaling end values (limits) of
the 15−bit digital value in the output word is scaled linearly to
12 bits. The resulting value is available after D−A conversion
as an analogue output signal (see section 5.4.5, Fig.5/5).
Data format VZ + 12 bits right−justified"
The 12−bit digital value in the output word is available after
D−A conversion as an analogue output signal (see also sec
tion 5.4.1, Fig.5/3).
Data format VZ +15 bits left−justified" and
data format VZ + 12 bits left−justified"
The 12−bit digital values in the output word plus the preced
ing sign bit are arranged left−justified in the data format (with
the three zeros at the end this results in a 15−bit data word
which, divided by 8, corresponds to the 12−bit digital value).
The 12−bit digital value is available after D−A conversion as an
analogue output signal.
The following diagram shows an example of the data format
VZ + 15 bits left−justified":
1
Digital output values
15−bit
2
Digital output values
12−bit (without three
zeros at the end)
3
Analogue output
signals
1
2
3
32760
0 4095
0
0 V
0 mA
4 mA 10 V
20 mA
20 mA
Fig.5/4: Example of data format VZ + 15 bits left−justified"